GE C70

CHAPTER 5: SETTINGS GROUPED ELEMENTS
C70 CAPACITOR BANK PROTECTION AND CONTROL SYSTEM – INSTRUCTION MANUAL 5-201
5
Figure 5-101: Phase directional logic
5.7.3.6 Phase current unbalance (ANSI 60P, IEC PVCB/PTOC)
SETTINGS  GROUPED ELEMENTS  SETTING GROUP 1(6)  PHASE CURRENT  PHASE CURRENT UNBALANCE
1(3)
The phase directional element responds to the forward load current. In the case of a following reverse fault, the
element needs some time—in the order of 8 ms—to establish a blocking signal. Some protection elements, such as
instantaneous overcurrent, respond to reverse faults before the blocking signal is established. Therefore, a
coordination time of at least 10 ms must be added to all the instantaneous protection elements under the
supervision of the phase directional element. If current reversal is of concern, a longer delay—in the order of 20
ms—is needed.
 PHASE CURRENT
 UNBALANCE 1

CUR UNBALCE 1
FUNCTION: Disabled
Range: Disabled, Enabled

CUR UNBALCE 1 DIF
SOURCE: SRC 1
Range: SRC 1, SRC 2, SRC 3, SRC 4, SRC 5, SRC 6

CUR UNBALCE 1 BANK
SOURCE: SRC 1
Range: SRC 1, SRC 2, SRC 3, SRC 4, SRC 5, SRC 6

CUR UNBALCE 1 INHNT
FACTOR A: 0.0000
Range: –0.1000 to 0.1000 in steps of 0.0001


CUR UNBALCE 1 INHNT
FACTOR C: 0.0000
Range: –0.1000 to 0.1000 in steps of 0.0001